1. Field of the Invention
This invention is directed to a method and apparatus for making a frozen food article, and particularly an apparatus which is maintained in a ready state for freezing, without having the freezing chamber at reduced temperature to prevent retention of portions of prior frozen food and to prevent the formation of rime ice.
2. Brief Description of the Prior Art
The conventional refrigerating or freezing device comprises a compressor which compresses a refrigerant gas such as Freon, ammonia or nitrogen which is then expanded into an evaporator to allow the fluid to expand and evaporate and in so doing absorb heat whereby an article may be cooled or frozen. This fluid is then again compressed and condensed and the cycle is repeated. In some cases, a container is surrounded by coils or is submerged in a liquid which has been cooled by a refrigerating apparatus so that an article placed in the container is either cooled or frozen. An example is seen in the U.S. Pat. to Spreen, No. 1,764,653. In this patent there is disclosed a refrigerating system which includes a compressor and an evaporator which is immersed in a liquid. Also, submerged in this liquid are containers into which articles to be cooled can be placed and maintained in a cooled or frozen state. Another example is seen in the U.S. Pat. to O'Neil, et al., No. 2,058,098. This patent shows a refrigerating and dispensing system whereby the evaporating coils surround a soda dispenser to cool the beverages so that upon demand the beverages may be dispensed into such containers as paper cups and the like.
In the U.S. Pat. to Palmer, No. 3,041,852, there is disclosed a refrigerating apparatus which is contained in one unit whereby the coolant is transferred via a coil to a separate container which, in the example shown, is a garbage container. Thus, a compressor and evaporative unit is contained in one unit and a separate container to receive the evaporative coolant is utilized to cool an article contained therein.
As will appear from the further portions of this specification, this prior art is not directly pertinent, but is generally directed to refrigeration systems for food materials. In addition, Ash U.S. Pat. No. 2,590,061 discloses a system wherein a fluid is maintained at a relatively constant temperature for dispensing to and cooling a remote vat but this fluid is not recirculated back to the reservoir, because the fluid is not a coolant. Bright U.S. Pat. No. 2,040,828 is similar to Ash, but it must be noted that the volumetric capacity of Bright's fermentation tank is substantially greater than the volumetric capacity of his cooling apparatus, which is largely opposite from the teaching set forth below. Furthermore, while Haley U.S. Pat. No. 2,720,084 employs a separate refrigerator for chilling a circulating coolant, the coolant is for air conditioning service and there is no teaching of a particular type of food freezing chamber.